Glauber oscillator and time travel

The standard quantum mechanics does not forbid time-travel. However, some alternative formulations (based on the so called “rigged Hilbert space”) include irreversibility as a fundamental principle: a quantum particle that decays cannot travel back in time.

There are not direct evidences of the irreversibility of decay processes, but the new quantum mechanics predicts that the decay rates are quantized.

If one observes the quantization of the decay rates, one can claim to have provided experimental support to the irreversible formulation of quantum mechanics.

In simple terms, one can claim that time-travel is not possible at the quantum level (…and also at the classical level).

Silvia Gentilini, Maria Chiara Braidotti, Giulia Marcucci, Eugenio Del Re, and Claudio Conti simulated in the laboratory one of the simplest models of the irreversible quantum mechanics, that follows an original proposal of Glauber. A laser beam emulates a quantum particle in a reversed harmonic oscillator, as a result the first experimental evidence of the quantization of decay time is reported in a paper published in Scientific Reports.

(reprint from the former website)

Time Travel is NOT Possible (press release)

Time travel is not possible*

Press release on the Templeton project, Generalized Uncertainty Principle and The Photon (2015-2018)

Our paper on the Glauber oscillator and Time Travel had a relevant impact in the press …

Comprehensive press release pdf files:

Rassegna stampa_cs_viaggi nel tempo (pdf 1)

Rassegna stampa_cs_viaggi nel tempo (pdf 2)

*maybe, if you are subnuclear particle in proximity of a supermassive black hole you may have some chances to go back in time for a femtosecond

Nonlinear dynamics of optical frequency comb (PRIN project NEMO)


The┬áPRIN project “NEMO” started. The topic is “Nonlinear Dynamics of Optical Frequency Comb” coordinated by Prof. S. Wabnitz (Univ. of Brescia), in collaboration with Prof. L. Pavesi (Univ. Trento) and Dr. De Rosa (INO-CNR).


Physics without equations? (school/workshop at ROME!)

July 24 – August 4

People think that equations are not needed if we have a lot of data and the way to organize them… is this true?

Are equations useless for complex systems?

Are computers able to derive models for complex-systems more effectively than humans?

We are announcing the International School and Workshop in collaboration with the University of Washington in Rome!

Data-Driven Methods for Multi-Scale Physics and Complex Systems

An interdisciplinary initiative aimed at committing together different disciplines with the data-driven physics!

Lasing in curved geometry

A paper by Hong et al reports about lasing emission on modes sustained by local curvature.

The use of geometrical constraints opens many new perspectives in photonics and in fundamental studies of nonlinear waves. By implementing surface structures in vertical cavity surface emitting lasers as manifolds for curved space, we experimentally study the impacts of geometrical constraints on nonlinear wave localization. We observe localized waves pinned to the maximal curvature in an elliptical-ring, and confirm the reduction in the localization length of waves by measuring near and far field patterns, as well as the corresponding dispersion relation. Theoretically, analyses based on a dissipative model with a parabola curve give good agreement remarkably to experimental measurement on the transition from delocalized to localized waves. The introduction of curved geometry allows to control and design lasing modes in the nonlinear regime.